1. Field
Example embodiments relate to an apparatus for controlling an engine system and a method of controlling the same. More particularly, example embodiments relate to an apparatus and method of controlling a boost pressure and an intake air amount in a diesel engine.
2. Description of the Related Art
Currently, diesel engines may be equipped with a variable geometry turbocharger in which a turbine is rotated by an exhaust gas flowing in an exhaust pipe and a compressor connected to the turbine via a shaft is rotated to compress an intake air, thereby perform supercharging. Also, the diesel engines may be equipped with an exhaust gas recirculation (EGR) system which recirculates a portion of the exhaust gas to a combustion chamber to efficiently reduce NOx.
In a conventional engine management system, PID (proportional integral derivative) controller dedicated to VGT (variable geometry turbocharger) and PID controller dedicated to EGR may be used independently to each other.
A conventional PID controller may have lookup tables for P, I, D gain and use optimal P, I, D gain adapted for a working situation. However, a huge number of tests may be required to obtain the optimal lookup table, to thereby increasing development periods and costs.
Further, since the variable geometry turbocharger (VGT) and the EGR system may be physically coupled to each other, a coupling effect of VGT and EGR may need to be considered together. However, a conventional controller in the diesel engine system may ignore the coupling effect and control the VGT and EGR independently, so that it may be difficult to perform a precise and accurate control, especially in a transient operation.